Growing Dockrillias

Every Which Way But Loose .. My Guide to Growing Dockrillias

Neville Roper

I could never say that Dockrillias (Docks) are rapid growers but I am convinced that they are closest orchid to indestructible as long as they are not grossly overfed or over watered. I have been growing Docks for over thirty years with some success and have become an admirer of the excellent hybridising done by Phil Spence. Phil has produced many wonderful hybrids using both Australian and New Guinea species to increase the range of flower colours and create a much extended flowering season. The orchid world dearly needs someone to take over from where Phil hung up his toothpick. To this end I am informed that some Victorian growers are doing some good work.

The simple answer as to how I grow these interesting orchids is, with apologies to Dirty Harry, summed up in the title as I have grown them or seen them grown using almost every method possible with the one absolute – they must be firm in the pot or tied securely to a mount or they will never establish a good root system.

Pot Culture

My preference is for terra cotta and plastic mesh pots and when filled with a bark and pebble mix ( they don’t seem to be too keen on coir) with plants firmly settled in they can last indefinitely as long as the mix does not become sour. These pots are hung high under 70% shadecloth with the mesh pots being cheaper, easier to find hangers for and much less of a load on the greenhouse frame. With both of these methods it is surprising how often plants start to ‘escape’ through the plastic mesh or the drainage holes. This is a habit I like although some plant profiteers who buy large plants with a view to divide and sales bench do not.

Mesh pot – happy Terra cotta pots

Mesh / Gutterguard Pouches or Rafts

I use rolls of plastic gutterguard and green twist tie to construct cylinders or rectangular rafts filled with the usual bark and pebble mix. A wire hook is attached at the back to facilitate hanging on an A frame or similar construct. Plants can be fixed firmly to these using fishing line (not too thin), nylon lace, twist tie or stocking strips. Alternatively roots can be worked in through the mesh or a small flap can be cut into the mesh and the plant installed underneath. Mesh rafts have excellent drainage and are light enough to hang many plants before bringing down the roof. The downside of using mesh rafts is that they provide pretty easy access to insects. For this reason I currently favour the 5mm mesh version of gutter guard that seems to only come in brown. Depending on the mix used and fertilising/ watering regime these rafts can become sour (acidic) over time and may benefit from an application of spray lime or similar.
Some species such as Dock. striolata prefer to be mounted flat on the upper surface of a rectangular raft rather than vertically on the side of the mount. As plants outgrow their current mount it is an easy matter to attach the plant and mount to a new larger one. There are other mesh products such as oyster mesh that come in much wider rolls which would help in the construction of larger rafts.

Dock Tweetas on a mesh pouch then onto a large treefern clab (left)
Dock. striolata started on a flat mesh raft and then upsized to a larger raft (right)

Treefern Pieces

There are two suitable types of tree fern whose trunks can be cut up, aged and used for growing orchids. Dicksonia is often referred to as ‘soft tree fern’ and cyathea species or ‘hard tree fern’, my preference is for the latter as it does not stay wet as long as the soft variety and is more open in texture providing increased possibilities for root penetration.

Plants need to be tied firmly to the tree fern blocks that have already had a wire hookinstalled at the back, the usual ties ( fishing line, stocking strips etc.) can be used. I often deflask baby Docks. onto small pieces of tree fern which I then attach to a larger block as they become established.

Over time some tree fern tends to become sour and may need ‘sweetening’ with an application of spray lime. The usual signs of any medium becoming sour is a yellowing of leaves that eventually drop off for no other apparent reason. Remember that any tree fern must be sourced legally from licenced collectors or scrounged from neighbours who have suffered a tree fern casualty.

These Docks. have outgrown their virgin cork and have been upsized onto tree fern blocks
The mesh cylinder became too small so it was pushed into a tree fern pot.

Timber Slabs

This is not my favourite mount but many other growers prefer to grow their Docks on pieces of timber such as old fence palings, aged hardwood building offcuts and red cedar offcuts – if you can get them. I have found that the timber retains very little moisture and creates a weight problem if a lot of large plants are grown this way. Possibly this mount is more popular with people who have easy access to a suitable supply of offcuts.

Branch Pieces

Short lengths of branches (dead) can be used with great success. This Is particularly so if the branch is from a tree species that naturally grows orchids in the wild such as casuarina, callistemon or melaleuca. My experience has been that growth is excellent for a few years until the branch wood starts to decay leaving the bark to form a cylinder of rotten wood and or borer frass. Sometimes the bark, plus plant, fall off as the wood breaks away. Weight is also a concern with this type of mount.

Suitable trees such as paperbark or bottlebrush are often grown as street trees and when ‘arborists’ conduct their routine wire clearing activities there is opportunity to salvage some useful mounts.

Happily mounted on a 300mm piece of melaleuca (paperbark).

Virgin Cork

This is a very good mount although some pieces seem to sour very rapidly after a few years of growth. Being impervious to water there is difficulty in using lime to ‘sweeten’ older mounts, this also has some impact on the need to water more regularly. If you are prepared to monitor for this problem and can afford it this is an excellent medium to mount orchids on being light, aesthetically pleasing, easy to work with, long lasting and very orchid friendly –if only at first for some pieces.

Live Trees

I have always tied orchids of most genera to trees in my garden and they do spectacularly well ( the orchids if not the trees!). Best to avoid eucalypts as many are not suitable and any trees that shed their bark. My favourite tree for this is the humble lemon tree followed by bottlebrush, paperbark, jacaranda, live tree fern and frangipani. Once again plants need to be attached firmly to the trunk or a major branch preferably facing North or east.

Dock teretifolia growing naturally on a casuarina in my backyard.

Other Mounts

This is the “EVery Which Way” part as I have seen Docks grown on almost anything imaginable – that doesn’t move! These are not mainstream methods but include the following:

Polystyrene pieces. This certainly overcomes the weight problem and how often do plants growing in glasshouses lined with polystyrene send their roots straight onto the insulating foam?

Cork floor tiles although some have toxic glue ( be careful!)

Terra cotta or cement pots hung upside down with the plant attached to the outside.

Wine corks. This is a method I favoured until that nasty Mr. Stelvin invented screw on wine caps. The corks were hot glued into rafts with a small cup hook screwed into the back of one of the corks.

This wine cork raft has been attached to a tree fern block.

Some Final Thoughts

Watering/Fertilizing

I rarely do either except in the heat of summer as they are ‘set and forget’ orchids in my greenhouse. Potted Docks and those mounted flat get an occasional dusting with my regular 50:50 blood and bone and dolomite mix. The rest, those mounted vertically get an occasional watering using a Magamper ( inline attachment that slowly releases Magamp fertilizer). If your collection is small or you are totally devoted to your Docks I would recommend regular dunking of your plants mounts and all in a drum of water/fertilizer or lime ( depending on their needs) as a way of getting thorough wetting and drowning any hidden pests. I know of one good grower who refuses to use this method on the grounds that it would be any easy way to spread disease.Pests

The two major ones are scale and orchid (dendrobium) beetles. Scale are more of a problem on older dense plants where they settle in the base of the plant and persistent applications of one of the pest oils is the answer to the problem. Beetles have the annoying habit of ringbarking the middle 10mm of each new leaf and only vigilance can bring the joyous sound of beetle crunching under boot.

Light

Docks perform better under bright conditions and a good guide to suitable conditions is to give them enough light so that the outer leaves develop a slight purple tinge. The over exposed nature of most of the images associated with this article also give some guidance as to the level of light required.

However you look at it success with these tough, interesting orchids is summed up in the title…..”Every Which Way But Loose.”

This article is subject to copyright. Please contact Neville Roper if you wish to reproduce it in any form.